Shmupacabra is a very fast old-scrool scrolling shooter and a bullet hell. “Bullet hell” means that you have to evade a large number of bullets and only one hit means instant death.
The goal of each level is basicly just to survive a large army of incoming enemies and their bullets and eventually to destroy an end-boss at the end of each level. You play each level in chronological order.
You have three attack modes: normal fire, constant fire and discharge. Both fire modes fire projectiles in front of you but constant fire makes you move slower. Discharge destroys everything, even bullets around you, but needs a long time to reload and is used only as a last-resort weapon.
When you destroy enemies, they may leave stars behind. You get extra-lives if you collect plenty of them.